Optical block



FIG. 1 is a perspective view of an optical block.

FIG. 2 is a side elevational view of the optical block, the opposite side being a mirror image thereof.

FIG. 3 is a top plan view of the optical block.

FIG. 4 is a rear end elevational view of the optical block; and,

FIG. 5 is a front end elevational view of the optical block.

The bottom of the optical block forms no part of the claimed design. 

CLAIM We claim the ornamental design for an optical block, as shown and described. 